Formation of flora and fauna on Earth

2013

10

Nov

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Many modern scholars suggestThat the Earth was formed about 4.5 billion years ago and life on it has developed steadily. and their remains were found in silica, which has an age of about 3.8 billion years old. The earliest inhabitants of the world were prokaryotes, organisms like bacteria. These animals did not use oxygen for respirationas at the time in the world it was not. Food source for them were organic compounds that formed on Earth during its lifelessness by ultraviolet radiation and volcanic eruptions. Another source of power for them to become inorganics. Arose quite early photosynthesis, which usesAli bacteria as an additional source of hydrogen ions. While life looked like a thin bacterial film is placed on the bottom of ponds and other wet areas.

Eukaryotes

It is still not known when he first appeared eukaryotes , whichin contrast to the prokaryotes has been issued kernel. Scientists suggest that it happened somewhere in 1.5 billion years ago, but recently made discoveries and found the remains of cells, which is about 2 billion years. Eukaryotes , as scientists assume, were the result of a merger of their ancestors with some aerobic bacteria . Thus, there was the formation of mitochondria .

The earliest eukaryotes – unicellular algae and fungi spread very quickly in the Proterozoic era (2500 to 541,0 ± 1,0 million years ago) and at the same time began to appear the very first mnogokletfull-time. About 1000-600 million years ago the planet was quite rich fauna, which was presented to jellyfish, molluscs and polyps . Some found the remains of organisms today can not be attributed to the existing types of Animal . Not all classes and types of animals, which were formed at the time couldwhether to live up to the present day.

Becoming a person on the planet

Thus, the continued development and colonization of our planet and to this day do not survived a large number of Animal , evidence of life which we find to this day. Today still continue cnOra among scientists about the causes of extinction of Dinosaur in the Cretaceous (145,0- 66.0 million years ago) The very first assumption is considered climate change on the planet. But also according to some scholars suggest that dinosaurs lived on the planet in the Cenozoic era, which is considered the era of a new life. It is in this periodwas the peak of the vegetation and the emergence of a large number of mammals .

It is in the Cenozoic era were all living in the moment, in the world mammals and birds . The biggest sunrise occurs at the beginning of the Neogene period, which occurred 25 million years ago.It was at this time appeared the first apes . In the future, significant cooling occurred after the extinction of a large number of heat-loving. About two million years ago, a new era began, which was the beginning of the formation and development human , which we know under the name of antropogen.